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        .module basic_int

test_ctl_port     = 0x80
print_port        = 0x81
int_timeout_port  = 0x90

        .area BOOT_VEC
        
        jp      main
        
        .area INT_VEC

int_entry:
        exx

        ld      b, a
        ld      hl, #int_seen_str

print_str:
        ld      a, (hl)
        cp      #0
        jp      z, print_str_exit
        out     (print_port), a
        inc     hl
        jp      print_str

print_str_exit:
        ld      a, b
        exx

        ld      h, #1
        reti

        .area _CODE

main:
        ld      h,  #0
        ld      bc, #100
        ld      a, #50
        out     (int_timeout_port), a

test_timeout_loop:
        ld      a, #1
        cp      h
        jp      z, test_pass
        
        dec     bc
        jp      nz, test_timeout_loop

test_fail:
        ld      a, #2
        out     (test_ctl_port), a
        .db     0x76            ; hlt

test_pass:
        ld      a, #1
        out (test_ctl_port), a
        .db     0x76            ; hlt
        
        .area _DATA

int_seen_str:
        .ascii "Interrupt asserted"
        .db    0x0a
        .db    0x00